$ git clone -n https://src.fedoraproject.org/rpms/ruby-gnome2.git /var/lib/mock/f40-build-772778-126632/root/chroot_tmpdir/scmroot/ruby-gnome2
Cloning into '/var/lib/mock/f40-build-772778-126632/root/chroot_tmpdir/scmroot/ruby-gnome2'...
$ git fetch origin 6080a7ab12e31871aec5a1725b48e43ba408ed1f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ruby-gnome2
 * [new ref]         6080a7ab12e31871aec5a1725b48e43ba408ed1f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6080a7a Fix C compatibility issues (#2256908)